title: Pedunculopontine nucleus evoked potentials from subthalamic nucleus stimulation in Parkinson's disease.
abstract: The effects of subthalamic nucleus (STN) stimulation on the pedunculopontine nucleus area (PPNR) evoked activities were examined in two patients with Parkinson's disease. The patients had previously undergone bilateral STN deep brain stimulation (DBS) and subsequently received unilateral DBS electrodes in the PPNR. Evoked potentials were recorded from the local field potentials (LFP) from the PPNR with STN stimulation at different frequencies and bipolar contacts. Ipsilateral and contralateral short latency (<2ms) PPNR responses were evoked from left but not from right STN stimulation. In both patients, STN stimulation evoked contralateral PPNR responses at medium latencies between 41 and 45ms. Cortical evoked potentials to single pulse STN stimulation were observed at latencies between 18 and 27ms. These results demonstrate a functional connection between the STN and the PPNR. It likely involves direct projections between the STN and PPNR or polysynaptic pathways with thalamic or cortical relays.
authors.affiliation: Toronto Western Research Institute, University Health Network, University of Toronto, Canada.
authors.forename: Bogdan
authors.initials: B
authors.lastname: Neagu
authors.forename: Eric
authors.initials: E
authors.lastname: Tsang
authors.forename: Filomena
authors.initials: F
authors.lastname: Mazzella
authors.forename: Clement
authors.initials: C
authors.lastname: Hamani
authors.forename: Elena
authors.initials: E
authors.lastname: Moro
authors.forename: Mojgan
authors.initials: M
authors.lastname: Hodaie
authors.forename: Andres M
authors.initials: AM
authors.lastname: Lozano
authors.forename: Robert
authors.initials: R
authors.lastname: Chen
mesh_terms: D046690:Deep Brain Stimulation; D004567:Electrodes, Implanted; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000033:anatomy & histology / Q000502:physiology*; D010300:Parkinson Disease / Q000628:therapy*; D045042:Pedunculopontine Tegmental Nucleus / Q000033:anatomy & histology / Q000502:physiology*; D020531:Subthalamic Nucleus / Q000033:anatomy & histology / Q000502:physiology*
keywords: DBS; Field potential; LFP; PPN; STN